Review on 🔋 NOCO GENIUS2X4 Smart Charger: 4-Bank, 8-Amp (2-Amp Per Bank), Fully-Automatic Battery Charger & Maintainer for 6V and 12V Batteries. Includes Trickle Charging, Desulfator, and Temperature Compensation by Miro Dadee

I bought this as a 6v battery maintenance tool because it claims to work on 6v. I haven't seen that every time you turn the power off or on you have to press and hold the bottom for 3 seconds to activate the 6 volt charge. Once every 4 times for each battery. Batteries are harder to keep charged. The good news is they look good.